Tree hogger unit

ABSTRACT

A mobile tree hogger unit having a masticator assembly with a pair of feed drum units which cooperate to feed tree parts to the masticator for reduction to mulch size chips. The feed drum units are on frames which are adjustably hinged to the hogger unit chassis in such manner as to enable the drum units to be both angularly and elevationally positioned relative to the chassis.

United States Patent Inventor Routhtord J. Burkett Indio, Calif. Appl.No. 699,655 Filed Jan. 22, i968 Patented Jan. 19, 1971 AssigneeCoachella Valley Organic Fertilizer Co. a corporation of California TREEHOGGER UNIT 9 Claims, ll Drawing Figs.

U.S. Cl. 241/ 101, 56/503 lnt.Cl..... .B02c 19/12, B02c 23/02 Field ofSearch 24 l /(Mob Crusheiliseisldl. IS7-91231,(CQISQEYL 232(Cursory),28`6, V289, 281, 301; 56/16, 17, 503, 119; 144/246, 249, 250, 162, 172,3-4

References Cited UN lTED STATES PATENTS 8/1953 ll/l953 ll/l955 ShaferManin.

Karlsson Nicholson Kautz Standal. Juno Angus Primary Examiner-Donald G.Kelly Attorney-Warren, Rubin, Brucker and Chickering ABSTRACT: A mobiletree hogger unit having a masticator assembly with a pair of feed drumunits which cooperate to feed tree parts to the masticator for reductionto mulch size chips. The feed drum units are on frames which areadjustably hinged to the hogger unit chassis in such manner as to enablethe drum units to be both angularly and elevationally positionedrelative to the chassis.

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Y snm 3 nF 5 INVENTOR Routhford J. Burkett BY www@ Mami Attorneys snmuur 5 mwsNmR, A Routhford J. Burke" PATENTEUJAMQM 3553422 SHEE 5 UF 5INVENTOR. Roufhford J. Burkett BY www] WMU Attorneys TREE HOGGER UNITThe invention, for which the following represents a detailed disclosure,relates to a tree hogger unit for reducing tree parts, including theroot ball and trunk, to mulch-size chips, and more particularly to sucha device which is mobile, and thus capable of masticating entire treesat the place where the trees are actually felled. o

Tree removal carries with it the problem of disposing the tree onceremoved. It is common practice-to saw the tops of trees to be removedaway from the trunk and then saw the trunk itself into pieces which aremore readily capable of being handled by conventional means. The foliagewhich comprises the top of the tree is then reduced, in some convenientmanner, for handling, and then transported from the site. While thetrunk of the tree may be used as fire wood, or similar purposes, thefoliage is usually burned or dumped in some outoftheway place. Where thewood from the trunk of the tree is not needed, it likewise mustbedisposed of, and the men and machinery required for this purpose isconsiderable.

Recent experiments incitrus grovesdemonstrate the advantage of periodicpruning of the grove by removing certain of the fruit trees. It has beenfound that, where the trees are initially planted with approximately to100 to 200 trees to the acre, that as the trees mature their fruitbearing capability may be increased substantially by the strategicremoval of certain of the trees in the original planting. Specifically,lit has been found that removal of every other tree in a row actuallydoubled the production of a grove with only one-half the number oftrees. As the trees in a grove mature they tend to crowd one another. Ithas been found that the'skirt of the tree, i.e. the peripheral area ofoverhanging branches, is the most productive portion of the tree. Thus,overcrowding tends to reduce fruit bearing capability. Removal of`certain of the trees in a grove relieves this overcrowded condition andpermits the trees to reach their optimum fruit bearing capability andincreased productivity is achieved.

Because of the initial closeness of the trees in an orchard, it

is both expensive and difficult toremove' large numbers of treestherefrom, and this is especially so'of trees deep within the grove. i.

lf, for example, the trees, upon being felled, were dragged from thegrove, the branches comprising the skirts of the remaining stand wouldbe damaged. Thusfprior to the present invention, it was necessary to cutup the trees in the grove and drag them out piece by piece. It is anobject of the present invention in view of the foregoing to provide acompact mobile tree hogger which is capable of going'into a grove oftrees and reducing felled tree parts at the site without damage tosurrounding trees.

Devices are known which are designed to masticate small limbs andbranches disposed in windows. Exemplary of such Y devices is theconstruction shown inAtmore U.S. Pat. No. 2,925,703. The Atmoredisclosure is unequivocably directed to a construction which is intended,solely to masticate loose brush disposed in windows.

Moreover, no increase in horsepower could render Atmore capable ofmasticating tree trunks or root balls. Accordingly, it is another objectof the invention tov provide a tree hogger which is selectively operableto engagetree parts irrespective of substantial size variations andcontinuously and positively Another, and still further object of thepresent invention` is to provide a tree hogger which is highly efficientand is so constructed as to be extremely durable, and effective toreduce entire trees to usable mulch in a single operation once the treehas been felled.

Trees, even of the same variety, may vary in size and to some extent inhardness, and it is an-additional `object of the present invention toprovide apparatus which is capable of adjusting to various positions ofthe felled tree to assure proper mulching and is further constructed toavoid breakdowns due to overloading as a consequence of the size orhardness of the wood being masticated. Y

These and other objects and advantages of the present invention willappear from the following'detailed description. when read in conjunctionwith the drawings, wherein:

FIG. l is a side elevation of a tree hogger unit construction inaccordance with the present invention; i

FIG. 2 is a top planview of the unitof FIG. l;

FIG. 3 is an enlarged fragmented,and partially sectioned view of thefeed and control assembly for the masticator;

FIG. 4 is a section of FIGA. 3 taken along lines 4-4 of FIG. 3;

FIG. 5 is an enlarged and sectioned view of the frame hinge andelevating mechanism; L

FIGS. 6, 7, and 8 comprise a series vof views illustrating the action ofthe hogger unit of FIG, l as it approaches and masticates a tree; and

FIGS. 9, 10 and ll are top plan views of FIGS. 6, 7 and 8 respectively,partially fragmentedto illustrate the action of the moving parts of theapparatus.

While the invention is susceptible vof' various modifications andalternative constructions, a particular illustrative embodiment is setout in the drawings and will be described in detail hereinafter. It willbe understood that lthe invention is not in- -tended to be limited tothe particular disclosed form, but rather to cover all modifications,alternative constructions, and equivalents falling within the spirit andscope of the invention as expressed in the appended claims.

feed all such parts to a masticator 'assembly which comprises a portionof the hogger unit.

Still another object of the present invention is the provision of animproved apparatus for pruning groves of trees and otherwise effectingtree removal and on site reduction to form a useful byproduct.

It is a further object of the present invention to provide a tree hoggerof the type herein described, which is mobile, and therefore, capable offunctioning at the sight where the tree is actually felled. An objectrelated to the foregoing is the provision of a hogger device which isreadily controlled by one man and maneuverable with a dexterity whichpermits its convenient use in citrus orchardsl where .maneuvering spaceis limited.

With reference now to the drawings, a mobile tree hogger unit isillustrated in detail` and comprises a'chassis disposed on front andrear wheeled axles, the rearone of which is steerable and powered totransport the chassis. An internal combustion engine is mounted on thechassis and drives a masticator unit, also mounted on the chassis, whichreduce trees and the like to small chips. A feed and control assembly isprovided for urging trees into the masticator` The feed and controlassemblies are adjustable to position the lsame to permit optimum.positive control of the tree as it is being fed to the masticator.

With particular reference to FIG. l, a' tree hogger constructed inaccordance with the present invention is indicated generally at l5 andcomprises a chassis 17 disposed upon front and rear axles 18 and 19,respectively, and both axles are supported by wheels 20 at the endsthereof. The forward axle 18 is solid, and secured to the chassis 17 bymeans of any suitable suspension system (not specifically illustrated).The rear axle 19 is live, being drivable by means of a fluid motor 22.In order to render the chassis steerable, the rear axle 19 .is supportedon either side of the differential housing by axle connecting meanscomprising a yoke 24, which connects to a single, centrally disposedpillar 26 so as to be rotatable about the pillar. An internal combustionengine 27, which may be of either a diesel or spark ignition type, ismounted on the chassis, in this instance, above the rear wheels, and iscontrolled from the' operator's position, indicated generally at 29.

The engine serves the dual function of driving a large masticatorassembly, indicated generally at 3l, and the fluid pressure pumps whichprovide the motive power for the unit. The masticator is driven, in thisparticular instance, from a main pulley 33, connected to theengine-crankshaft, which drives belts 34 connected to the masticatorpulley 35. In order to minimize slippage, a series of V belts may beemployed, as best seen in FIG. 2. 5 The masticator assembly 3l iscomprises a masticator drum indicated generally at 40 (see of a knownconstruction, and

FIG. 2) disposed on a shaft 42 for rotation in a housing 44. The shaft42 is journaled in a' sidewall 46 and 47 of the housing, and the pulley35 is keyed or otherwise attached to the shaft for rotating the same.

The drum itself comprises a pair of rtruncated conic sections 49 mountedon the shaft so as to converge at the center thereof, and teeth 50 areformed about the periphery of the sections 49 having sharpened edgeswhich are aligned so as to cut as the drum is rotated, in this instance,counterclockwise as seen in FIG. l. The masticator is constructed ofheavy material and is balanced, and acts like a flywheel so as to berotatable at relatively high speeds thereby developing substantialmomentum. Accordingly, the masticator is sufficiently powerful to reducetree trunks to mulchsize chips.

In contrast to brush disposed in windrows, entire trees arecomparatively heavy, and present unique handling problems due tosubstantial size variations from root ball to trunk. Itis necessary,therefore, to maintain continuous and positive control of the tree partsin order that they may be fed to the masticator. This is accomplished inkeeping with the invention by means of a novel feed and control assembly55 disposed at the forward end of the chassis immediately in front ofthe masticator. Controlled feeding of a tree to the masticator isaccomplished by the assembly 55 by engaging the tree with a pair of feeddrum units indicated generally at 57 and 58. The drum units 57 and 58are supported for rotation on feed drums support frames 60 and 6lrespectively, attached to the chassis. The frames are, in the structureillustrated, formed of heavy steel plate, and as may be seen in FIG. 3,comprise a yoke having a main support member 63 and transverse upper andlower supporting members 64 and 65, respectively. The main memberincludes a flat plate 66 which acts as a guide to the throat of themasticator.

The drums, as may be seen in FIG. 4, comprise cylinders 67 having aseries of axially extending radially disposed blades 69, and as seen inFIG. 3 a peripherally disposed continuous helical blade 70 which extendsover about one-third of the height of the drum, beginning at the bottom.The cylinders 67, are mounted on driveshafts 72, and in order to permitfree rotation thereof under loading during feeding of the heavy treeparts, the drive shafts are joumaled both at the bottom, in a bearing74, and at the upper end in a bearing disposed in the transverse member64, the cap for which is seen at 76.

The blades of the drum are adapted to positively engage the tree bypenetrating at least the bark, lift the same to a position in alignmentwith the masticator throat, and feed the same toward the masticator. Inorder to provide the controlled force necessary to this function, thedrums are preferably driven by fluid motors 78 which are secured withrespect to transverse member 64, by pal plates 80. The motors areprotected against damage from limbs by shrouds 81, which also assist indeflecting limbs toward the masticator.

Because of the heavy, and uneven loading to which the drums aresubjected by virtue of the variation in size and density of various pansof the tree being masticated, and in order to compensate for limiteddrum shaft deflection, the upper ends of the shafts 72 are connectedwith their respective drive motors by means of a flexible couplingassembly 82. Various types of flexible drive couplings are known. Theillustrated assembly comprises a pair of identical gears disposed inopposed face-to-face relation with one gear being on the fluid motorshaft, and the other being connected with the top of the shaft 72. Acontinuous chain is then disposed about the gears with the linksengaging the teeth thereof. This arrangement provides powertransmission, while permitting some misalignment of the shaft. It alsomay serve as overload protection in that the chain may be designed withpins having a predetermined shear strength which, when exceeded, willcause severance of the chain and thus the drive between the motor anddrum. In this manner, the drum and the fluid motor are protected againstoverload which might occur when the power necessary t'o draw the treeinto the masticator exceeds the strength of any of the vital feedingelements.

The use o of fluid motors, such as indicated at 78, provides theadditional desirable feature of permitting' independent control of eachof the drums. Accordingly, should-one drum become loaded more that theother, individual. c ontrol of these mt motors permits necessaryapplication of fluid under pressure to compensate for the unevenloading. Moreover. since the drums 57 and 58 are rotated oppositely, theformer being rotated clockwise as seen in FIG. 4, and the latter beingrotated in a counterclockwise direction, this is readily accomplished bythe use of individual motors, and eliminates thc need ofa differentialgear arrangement-which might otherwise be required. f

The use of individual drive motors for the drums provides still anotheradvantage in that the tree parts may be fed t0 the throat of themasticator smoothly despite discontinuities in the tree structure. Sincea tree,v is seldom absolutely symmetrical one drum may be required toroll farther than the other during part of the feeding process. In orderto maintain proper treeto-masticator alignment, one drum may be requiredto go faster than the other at certain times. With individuallycontrolled fluid motors,it is possible for the affected drum to speed upor slow down individually, to maintain the tree on its proper coursethrough the drums. Once past the drums, a stationary plate assembly 82which includes deflector plates 83 and 86, which converge toward thethroatl of the masticator, guide the tree smoothly.

In practice, the tree to be fed to themachine has previously beenuprooted, such as by a bulldozer and is disposed on its side, when theit is allowed to'dry for approximately 5 days. Consequently, a root ballof substantial diameter is initially presented to the hogger and that isfollowed by the trunk of the tree which is of considerable lessdiameter. The apparatus of the present invention in is constructed to beselectively controlled to accommodate changes in diameter, by varyingthe opening between the drums, and thereby permit positive anduninterrupted control of the tree parts throughout the chipping process.With reference now to FIG. 4, it will be seen that frame 60 and 61 arepivotable so as to adjust the relative position of the drums and permitcontinuous contact with the tree irrespective of its diameter at anyposition along its length measured between the drums themselves.

In accordance with this feature of the invention, frame members 60 and6l' are pivotally mounted about elongated hinge pins 84 and 85respectively. The pins 84 and 85 interconnect the chassis and framemembers by passing through intermeshing cylindrical bosses 87 on theframe, and 88 on the chassis. It will be seen in FIG. 3 that the hingepin 84 and 85 are parallel with the shafts 72 of the drums, therebymaintaining the predetermined angle of the drum with respect to theground which, as may be seen in FIG. 3, is approximately 75.

As previously lexplained, it is necessary to efficient operation tomaintain positive engagement of the drums with the tree at all times asit progresses toward the masticator. Since the drums are freelypivotable about the hinge pin 84, they may be positively urged intoengagement with the tree as it passes between them. This is accomplishedby means of fluid motors 89 and 90.

The motors, as may be seen in FIG. 4, comprise hydraulic cylindershaving reciprocable Vrams 91 extending from the cylinder body, andengaging in eyelet 93 rigidly secured to and outwardly extending boss 95on the drum mounting frames. A clevis 97 affixed to the end of the ram91 engages the eyelet by means of a pin 99 to complete the connection.The cylinder is grounded to the chassis by means of a clevis 101 whichsurrounds an eyelet 102 and is secured thereto by means of the clevispin 103. Thus, predetermined directional application of fluid to themotor 89 results in extension or retraction of the ram, causing the drumframe to be pivoted about the pin 84. ln this way the operator mayspread the frames to initially open the device to receive the root ball,and then move the frames together so that the drums positively engagethe tree. Moreover, as the cross-sectional dimension of the tree varies,the operator may adjust the drum frame positions accordingly so thatcontinuous positive engagement with the tree is constantly maintained. i

The drum and frame assemblies are heavy, and the drums themselvessupported topl and bottom in bearing capable of handling the loads vtowhich the drums are subjected. Moreover, the frames are constructed witha number. of degrees of freedom of movement, and such movement would beimpaired if the frames were on the ground. Accordingly, the drums arenot'constructed to engage the ground or pick up material directlytherefrom.

A tree disposed on its side-after being uprooted not only differs indiameter as measured along the line between the shafts 72, but also mayvary in its height relative to the ground upon which it has been felled.ln orderto render the feed `assembly 55 capable of-'picking up the partsand feeding them to the masticatonthe position of the drums, are inaccordance with the invention `also rendered vertically adjustable withrespect to the ground. This limited adjustability ofthe relative heightof the drums thus permits the operator to make effective use of theblade geometry of the drums irrespective of the height of the tree fromthe ground. indeed, having once engaged a part thereofwith the drums,the operator can lift thatpart to an extent prior to rearward feedingthereof. l

With reference now to FIGS. 1, 3, and 5, it will be seen that theknuckles or cylindrical bosses 87 on the chassis and drum supportingframes respectively are spaced from one another, and contrary to typicaldoor hingel arrangements do not ride against one another. This spacingprovides a. sliding hinge connection which permits limited heightadjustment of the support frames and thus the drums themselves.Heightadjustment for each drum is accomplished by means of a fluid motor 105having a ram 107 extending therefrom, and pivotally attached by means ofa clevis and eyelet arrangement 108 tothe top transverse member 64of thesupporting frames. The cylinder of the fluid motor 105 is pivotallymounted at 109 to the chassis, and it will be appreciated that extensionor retraction of the ram 107 will cause limited elevation or lowering ofthe drums to permit their proper positioning with respect to eachportion of the tree as it is fed to the device.

lt is an additional attribute of the tree hogger, which comprises thepresent invention, that it is operable from the control position 29 byone man.v s seen in FIG. 2, the internal combustion engine is connected,through a power takeoff 112 tohydraulic pumps 114 and 115. ln theinstance shown, the power takeoff includes a main driven pulley 116connected to the drive shaft by belts 117, and is connected Ato a shaft118 journaled in pillow blocks 119 and 120, respectively. A transferpulley 121 on the opposite end of the shaft drives the pump 115 by belts122, and a second pulley on the shaft for vpump 115 drives pump 114 bymeans of belts 123. The pumps 114 and 115 provide the tluid pressure notonly to drive the motor 22 and drum drive motors, but also thepreviously described fluid motors which control the positioning of thedrums 57 and 58. All of these functions are performed by means of aseries of control levers 125 at the convenient disposal of the operator.

With the masticator and feed assembly 55, disposed forwardly, the rearwheel drive and steering which forms a part of the chassis permits readyalignment of the chassis with the longitudinal axis of the felled treesto be fed to the device. Steering by means of the axle 19 isaccomplished by a fluid motor 130 which is connected between the yoke 24and the chassis frame. The employment of any well-known valvearrangement connected to the steering wheel 132 controls both thedirection and pressure to be applied to the fluid motor 130 therebypermitting a natural "feel of the road through the steering wheel 132.Moreover, the use of fluids, such as hydraulic oil, permits not onlyindividual control of the various operative functions of the device froma single, essentially constant speed prime power source, such as theinternal combustion engine 27, but effectively prevents damage due tooverload, a feature which would not be as effective through the use ofmore conventional gear drives and like transmission elements. Thus, theuse of hydraulics permits a degree of flexibility in compensating forthe irregularity commonly encountered in operations of the type forwhich the device has beenconstructed.

`With reference to FIGS. 6 and ll, the hogger unit is there shown in aseries of views illustrating its approach to, and consumption of, anexemplary tree. Particularly in FIGS. 9, l0 and ll, it is possible tosee the relative movement of the drums toward and away from cach otheras the drumsare continuously urged into contact with the tree itself` lnFIGS. 6, 7 and 8 the machine is advanced as the tree is consumed. Whilethe device is sufficiently powerful enough Ato draw an` entire tree intoit while stationary, the chips expelled beneath the masticator would bevmore useful if spread out.

Thus, by simultaneously moving the vehicle forwardly at a predeterminedrate,A the chips are spread out and do not simply accumulate in a largepile beneath the masticator. They may then be sprayed with a bacteriawhich accelerates their decomposition, andfrnally distributed whereneeded.

lt will -be understood that the hogger unit of the present invention iscapable of reducing hardwood trees having trunk diameters in excess of16 inches with preliminary pruning or cutting. The entire tree isconsumed intact upon being allowed to dry for a period after uprooting.

lclaim:

l. ln a tree hogger characterized by a chassis having a y masticatorassembly supported thereon the combination comprising,

a pair of support frame means hingedly secured to the chassis adjacentthe masticator assembly-,

a pair of feed drum units, one mounted in each of said support framemeans and disposed generally parallel toone another for moving treeparts to the masticator assembly; and

selectively operable power-operated frame-positioning means operativelyassociated with said frame means for pivotally positioning said framemeans relative to said chassis and thereby varying the distance betweensaid drum units mounted in said frame means.

2. The apparatus of claim l wherein said drum units each comprise:

a drum shaft; and

a feed cylinder secured to said shaft for rotation therewith;

and further i f wherein said support framed means each comprise:

a main support member extending generally parallel t0 the axis ofrotation of said cylinders and vhingedly connected to the chassis;

a pair of transverse support members extending from Said main supportmember at locations spaced apart a distance approximately equal to thelength of said shaft; and

bearing means in said transverse support members in which said drumshaft is mounted.

3. The tree hogger of claim l further comprising an hydraulic motoroperatively associated with each of said drum units providing rotationaldrive therefor.

4. The apparatus of claim l further comprising: sliding hinge connectionmeans connecting said frame means to the chassis; and selectivelyoperable, power operated hinge positioning means disposed between saidframe means and said chassis whereby the position of said frame meansrelative to the chassis along said hinge connection means is selectivelyvariable.

5. The tree hogger of claim l further comprising:

a forward-wheeled axle located at and supporting the portion of thechassis which represents the direction of normal forward travel;

a rear-wheeled axle spaced apart from said forward axle and located atand supporting the rear portion of the chassis, relative to said forwardaxle;

axle-connecting means pivotally mounting said rear axle for movementabout an axis perpendicular to the direction of travel; and

power-operated steering means associated with said axleconnecting meansfor selectively rotating said rear axle about its axis of rotation forcontrolling the direction of travel ofthe hogger.

6. ln a tree hogger characterized by a chassis and a masticator assemblymounted on the chassis, the combination comprising:

a pair of feed drum support frames secured to the chassis,

said frames having a pair of spaced-apart bearing members; and a feeddrum mounted on each of said frames between said bearing members',

sliding hinge connection means securing said frames to said chassiswherein said frames are movable relative to the chassis in a directionalong said hinge connection; and

fluid motors connected between said frames and chassis for selectivelypositioning said frames along said hinge connections.

7A The tree hogger of claim 6 wherein said sliding hinge connectionmeans comprises:

spaced bosses formed on both said frames and the chassis;

a pin interconnecting said frame bosses and said chassis bosses therebypivotally mounting said frames with respect to the chassis; and

power means interconnecting the chassis and said frames, said powermeans selectively operable to move said frames relative to the chassisalong said pin and thereby vary the positions of said frames relative tothe chassis.

8. The apparatus of claim 6 wherein said sliding hinge connections meansare further described as having a hinge axis substantially parallel tothe axis of said feed drums.

9. The apparatus of claim 3 further comprising; flexible coupling meansjoining said motors to said drum units whereby said motors are protectedagainst damage due to minor misalignment of said drum units therewithdue to forces experienced by said drum units during operation.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 3 ,556,422 Dated January 19 1971 Inventor(s) Routhford J. Burkett It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 1, line 23, change "200" to 120.

Column 3, line 5l, after "by", delete pa1.

Column 4, line 1, after "use", delete o.

Column 4, line 5, after "these", delete mt.

Column 4 line 31, after "when" delete the.

Column 6 line 47, in Claim 2, change "framed" to -frame.

Signed and sealed this 11th day of' May 1971.

(SEAL) Attest:

EDWARD M.FLETGHER, JR. WILLIAM E. SCHUYLER,JR. Attesting OfficerCommissioner of Patents FORM PO-IOSO (iO-69) ust-0MM Dc 6037s

1. In a tree hogger characterized by a chassis having a masticatorassembly supported thereon the combination comprising; a pair of supportframe means hingedly secured to the chassis adjacent the masticatorassembly; a pair of feed drum units, one mounted in each of said supportframe means and disposed generally parallel to one another for movingtree parts to the masticator assembly; and selectively operablepower-operated frame-positioning means operatively associated with saidframe means for pivotally positioning said frame means relative to saidchassis and thereby varying the distance between said drum units mountedin said frame means.
 2. The apparatus of claim l wherein said drum unitseach comprise: a drum shaft; and a feed cylinder secured to said shaftfor rotation therewith; and further wherein said support framed meanseach comprise: a main support member extending generally parallel to theaxis of rotation of said cylinders and hingedly connected to thechassis; a pair of transverse support members extending from said mainsupport member at locations spaced apart a distance approximately equalto the length of said shaft; and bearing means in said transversesupport members in which said drum shaft is mounted.
 3. The tree hoggerof claim l further comprising an hydraulic motor operatively associatedwith each of said drum units providing rotational drive therefor.
 4. Theapparatus of claim l further comprising: sliding hinge connection meansconnecting said frame means to the chassis; and selectively operable,power operated hinge positioning means disposed between said frame meansand said chassis whereby the position of said frame means relative tothe chassis along said hinge connection means is selectively variable.5. The tree hogger of claim l further comprising: a forward-wheeled axlelocated at and supporting the portion of the chassis which representsthe direction of normal forward travel; a rear-wheeled axle spaced apartfrom said forward axle and located at and supporting the rear portion ofthe chassis, relative to said forward axle; axle-connecting meanspivotally mounting said rear axle for movement about an axisperpendicular to the direction of travel; and power-operated steeringmeans associated with said axle-connecting means for selectivelyrotating said rear axle about its axis of rotation for controlling thedirection of travel of the hogger.
 6. In a tree hogger characterized bya chassis and a masticator assembly mounted on the chassis, thecombination comprising: a pair of feed drum support frames secured tothe chassis, said frames having a pair of spaced-apart bearing members;and a feed drum mounted on each of said frames between said bearingmembers; sliding hinge connection means securing said frames to saidchassis wherein said frames are movable relative to the chassis in adirection along said hinge connection; and fluid motors connectedbetween said frames and chassis for selectively positioning said framesalong said hinge connections.
 7. The tree hogger of claim 6 wherein saidsliding hinge connection means comprises: spaced bosses formed on bothsaid frames and the chassis; a pin interconnecting said frame bosses andsaid chassis bosses thereby pivotally mounting said frames with respectto the chassis; and power means interconnecting the chassis and saidframes, said power means selectively operable to move said framesrelative to the chassis along said pin and thereby vary the positions ofsaid frames relative to the chassis.
 8. The apparatus of claim 6 whereinsaid sliding hinge connections means are further described as having ahinge axis substantially parallel to the axis of said feed drums.
 9. Theapparatus of claim 3 further comprising; flexible coupling means joiningsaid motors to said drum units whereby said motors are protected againstdamage due to minor misAlignment of said drum units therewith due toforces experienced by said drum units during operation.